\subsection{Analysis of existing tools regarding our project}
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The second step after the analysis of needs was to do some research about existing piece of software, that could be useful to our project. 
According to the identified needs we have decided to develop using \tech{Java}, consequently the binary executing file will be light and independent from the operating system.\sk\\
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Firstly, we have made researches about \tech{Graphviz}\footnote{http://www.graphviz.org}, a \tech{graph} visualisation tool indicated by our tutor. 
This program might have been interesting because of the similitude between the representation of graphs and \auto s. 
Nevertheless, we have judged it to complicated for our use, and therefore inappropriate to our project. Moreover, sources of \tech{Graphviz} are in language C, and then not useful to us.\sk\\
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We then have searched for other animators for \fsa. We found a program called \tech{FSMDesigner4}\footnote{http://sourceforge.net/projects/fsmdesigner/} which seemed quite interesting, unfortunately, the download link was broken. So we were not able to test it and see if it was really interesting.\\
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Our researches haven't stopped to executive pieces of software. We have searched helping source code as well :\sk
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One of the first discovered was called \tech{FSA Utilities toolbox}\footnote{http://www.let.rug.nl/~vannoord/Fsa/}. This program was written in \tech{Prolog} which is of a different programming paradigm.\sk\\
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The second source discovered seemed more hopeful because it was a \tech{Java} project : \tech{FSM SIMULATOR}\footnote{http://www.cs.binghamton.edu/~software/fsm/fsmdoc.html}. But unfortunately, after reading we have seensaw that only bytecode was available. Without any sources there wasn't much we could do. So, we haven't used this project as well.\\
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Finally, we were not totally without existing material to handle this project. A couple of years ago, Olivier developed an application based on the research of shortest paths in \tech{graphs}.
As we said earlier \auto s and \tech{graphs} are relatively close to each other, an \auto can be seen as a particular type of \tech{graph}.
Thanks to this closeness we could reuse parts of the visualisation.\mk\\